


I'll Keep You Safe

by Gautiers



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Established Relationship, F/M, Implied Sexual Content, Light Angst, Romance, Violence, and loves byleth so much, sylvain is overprotective
Language: English
Status: Completed
Published: 2019-10-25
Updated: 2019-10-25
Packaged: 2021-01-03 03:15:26
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,081
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21172514
Author URL: https://archiveofourown.org/users/Gautiers/pseuds/Gautiers
Summary: Sylvain loves his betrothed with more than words can say and respects his king with the utmost sincerity. But what happens when he's forced to pick between the love of his life and his duty bound to his ruler?





	I'll Keep You Safe

**Author's Note:**

> some light angst with my lover boy sylvain. not beta-read bc i have no beta reader atm lol. enjoy folks

“Sylvain, you need to go,  _ now. _ ”

“Byleth, I can’t leave --”

“You must. Please. I promise I’ll find you as soon as I can.”

Sylvain wanted to shake her, as though it would bring some sense to her mind. How could he possibly leave her in the middle of this bloody battle? Their numbers were already small as they were, though deep down, he knew that his battalion would bolster Dimitri’s slowly dwindling forces. Goddess, he knew that, but at the cost of Byleth’s possible demise? He wouldn’t. Couldn’t.

The lancer shook his head, unwilling to leave his beloved’s side. “Byleth, I can’t leave you. Not until I know you have enough reinforcements to hold them off until I return.”

Byleth’s brows furrowed and her eyes softened; this time, it was her turn to shake her head. “Sylvain, we can’t afford to wait. Dimitri and his men will be overrun on the hill if you don’t take our men and go.”

“And what about you? What will happen to us -- to  _ me _ \-- if I lose you?!”

He was losing his cool -- his fear and anxiety was bleeding into his voice. Just the prospect of losing something so dear to him filled him with an unspeakable amount of terror.

She rested a firm, but gentle, hand on his arm. “Sylvain, you know better than anyone what Dimitri means to this kingdom. Please, you must go now, before it’s too late. Do you remember our promise?”

“Byleth --”

“Do you?”

•••

_ The sweat after a lengthy night of making love had long since evaporated into the cool air of the North, leaving Sylvain and Byleth swathed in the fur blankets of their bed and cuddled close to share skin and warmth. He pressed absentminded kisses to her shoulder and laced his fingers between hers to hold her small body close to his.  _

_ “I love you,” he murmured gently, his lips feather light as he tickled her skin. _

_ Byleth chuckled, leaning her back further into his embrace. “That’s the 12 _ _ th _ _ time you’ve said that tonight.” _

_ “There’s nothing wrong with reminding you.” _

_ “I don’t need to be reminded. I know I’m well loved by you.” _

_ The smile she beamed upon him melted his already soft heart, and Sylvain couldn’t help but kiss her, sweetly and thoroughly. Byleth meant the world to him. She saw past his twisted nature and wholeheartedly accepted him as he was, and he was a better man because of her. He never thanked the Goddess for much, but he thanked her every day for the one woman who hadn’t betrayed him. _

_ Byleth pressed one more gentle, lingering kiss to his lips before tracing them softly with the tips of her fingers. “Sylvain.” _

_ There was a subtle drop to her voice, a change to the way she spoke his name. “If there ever comes a day when you have to pick between Dimitri and I in battle, I want you to go to Dimitri.” _

_ The man froze, barely registering Byleth’s request. “What?” _

_ “Whatever you do, keep Dimitri safe.” _

_ “Byleth, if it means putting you at risk, I --” _

_ “You  _ will _ go to Dimitri first and foremost. He’s too important for this country to lose right now, and you know that.” _

_ One of the many things Sylvain had learned about Byleth was that she stubborn when it came to her beliefs. He’d seen her hold steadfast in the face of change and uncertainty, and while he appreciated her devotion to what she believed in, it was times like these that that devotion frustrated him. _

_ Unwilling to fight with her while they were naked and entwined in their own sacred space, he merely nodded and kissed her again, hoping that no such depressing words would be spoken for the remainder of the night. _

_ ••• _

With great reluctance, Sylvain rode to Dimitri’s side faster than the wind gusting at his back. Byleth's smile lingered in his eyes as she saw him off before turning away to command her own battalion. 

_ "Promise me you'll keep yourself alive until I come back." _

_ "I promise. Now go." _

He and his men thundered onto the battlefield from behind the enemy, effectively pinching them between his and Dimitri's troops. In the distance, he saw a familiar flash of blonde hair, followed closely by a russet skinned knight as they continued defending their position, even going as far as pushing the enemy lines further back. The enemies began scrambling as their formation crumbled, and with the eventual loss of their leader, the rest of the forces disintegrated.

"Your Majesty," Sylvain panted, wasting no time seeking his liege after quelling this rebellion. Dimitri regarded him with a thankful eye.

"Sylvain, we couldn't have secured this hill if it wasn't for you and your men."

"Of course, however, I am asking for immediate leave to assist By -- the Archbishop's troops." Sylvain paused for a moment before bowing his head slightly. "Please."

The urgency and distress was clear on Sylvain’s face. Dimitri knew better than to keep him any longer.

"Raise your head," Dimitri urged. "By all means, take whatever men are able and go to her. I'll follow once we're settled here."

•••

The battlefield was a bloodbath by the time Sylvain returned. Bodies, both enemy and allies, littered the fields.

Sylvain could hear the blood pounding in his ears louder than the cries of fallen comrades in his ears. He searched frantically, fearfully, anxiously, every emotion tearing his insides apart. Hell, he may as well have been cleaved in half by an axe with how wretched he felt. 

As he tore through battalions of men attempting to skewer him, he cursed his duty to his King and his promise to Byleth for forcing him to abandon the love of his life. He would do anything for her, even if it meant he had to leave her, but this uncertainty, this limbo of not knowing where she was or how she was doing or if she had been cut down by some Adrestian mongrel ate away at him like acid. He needed to find her, quickly.

Sylvain’s horse, Tenebres, reared up on her hind legs and stomped down hard on the line of archers before her, their blood barely staining her midnight black coat as she whinied triumphantly over them. “Good girl,” Sylvain complimented breathlessly, wielding the Lance of Ruin at their side as she rounded and galloped across the fields to where a large crowd gathered. Part of him wanted to believe that Byleth was not there, but a nagging intuition said otherwise.

_ For the love of Goddess, _ he chanted, _ please let her be okay _ .

Amongst the Adrestian forces, Sylvain heard something that made his blood boil hotter than any lava or molten metal, made red into his vision, and made him more bloodthirsty than he’d ever been. “We almost have her! Break through and kill her!”

"Over my dead body," he roared, before charging head first into battle with his lance poised to kill and a  _ Ragnorok _ burning in his hand. The dark knight moved through the crowd like a demon straight from hell, cutting down foes without a hint of remorse, his only focus being Byleth and her safety. So long as she stood, he would be invincible. 

Then he heard her cry out.

He honed in on her like a beacon and watched in muted shock at the blade that protruded through her backside as she stood protecting a fallen soldier. Her blood trickled down the edge of the blade, her own sword plunged through the Adrestian general's chest. It couldn’t be. Was this real? Was the exhaustion of battle merely tricking his eyes?

He rubbed them, blinked blearily and -- Goddess, no.

Chaos ensued. Both sides had lost their leaders, and the battlefield came to a momentary standstill. Sylvain could hear Dimitri barking orders, could hear the cries of men being cut down, but nothing registered. Nothing mattered. 

Tenebres whinnied softly, carrying the stricken man past the carnage and to his love. 

"Byleth..." His voice was hoarse and broken as he dismounted, staggering his way to her. Goddess, he was going to be sick. This had to be a dream, a distortion of reality. Had someone cast a spell on him? Was  _ he _ dead? But her body was as real as the ground beneath him, even if it felt like it was falling apart.

"Sylvain?" Her voice was small.

"I'm here." He supported her body with his own shaking hands as they sunk slowly to the ground. "I'm here."

"Are you hurt?"

Was he  _ hurt _ ? Here she was with a sword stuck through her and she was asking about him? There were a thousand and one other things to be worried about, but her first thought was of him -- he wasn't sure if he should yell at her or cry.

"Who cares?" he spat, struggling to rein in his emotions, "We need to get you to Mercedes. We can talk after."

"And Dimitri?"

"He's alive.”

“Good. Thank you...”

“Byleth?" No.

"Byleth." Goddess, please.

" _ Byleth! _ " She slumped against him without another word.

•••

Useless. Sylvain was utterly useless. He cursed the fact that white magic was something he never excelled at, as his healing spells were mediocre in comparison to what Mercedes could do. If he’d known it would come to this, he never would have left her to begin with. 

As dawn began to filter through the windows at Garreg Mach, Sylvain was stirred from his wallowing at the sound of the infirmary door. A haggard-looking Mercedes emerged, her expression as pleasantly stoic as ever. 

The dark knight stood at attention. “How...is she?”

Mercedes merely smiled. “She’s healing well now. There was a lot of blood loss out in the field, but it’s nothing a few potions and some rest can’t fix. You’re free to sit with her, if you’d like. She was asking about you last night.” And with that, she left to get some much needed sleep.

Byleth’s room was quiet as she slept. Dawn was slowly seeping in through the windows, illuminating her already pale face and making the dark shadows beneath her eyes even darker. 

Sylvain quietly pulled a chair to her bedside and held her hand, seeking her warmth and touch. “You’re such an idiot, Byleth.” A huge, big-hearted idiot. He held her hand to his forehead and felt the emotion bleed into his voice. “Stupid. What would we do if you died?”

“...not dead.”

Her hoarse voice made him jump. “Byleth, you should still be sleeping!”

“It’s hard to sleep when my betrothed is calling me an idiot and stupid.”

“That’s because you are.”

His voice trembled as he uttered those words, and he buried his face into the sheets beside her, unsure what kind of face he was making. “You’re a huge, stupid, idiot. I can’t believe you.”

Byleth chuckles and rests a gentle hand in his hair. “I’m sorry I made you worry.”

“If I die an early death, it’s because of you.”

“Please don’t be so dramatic.”

“I could tell you the same thing!”

He glared at her, shaking. He couldn’t believe she had the gall to even say that. “You nearly died trying to play the hero. You were  _ stabbed _ and nearly bled to death in my arms, Byleth! How do you think I could live if you -- if --”

“Sylvain…”

He couldn’t see her past the tears in his eyes, and he felt ashamed. Here he was, acting like a petulant child while his love was confined to the bed, injured. This wasn’t fair to her. 

“I’m sorry, really,” Byleth murmured apologetically. She touched his cheek with her fingertips and gently wiped away a tear. “Making you worried was the last thing I wanted to do.”

“Yeah, well, you already did, so there’s that.”

The hand that pressed against his cheek was warm and soft and alive. He held her to him with his own, thankful to the Goddess that she’d spared Byleth that day.  _ Please, don’t take her from me any time soon _ .

Moving over in the bed, the mercenary motioned for Sylvain to join her. He kicked off his boots and climbed in, careful not to jostle her too much. Wrapping strong arms around slender shoulders, he pressed his lips to her hair and soaked up her warmth, hammering down the fact she was alive and well and in his arms in that moment. 

“Next time,” he mumbled, “you don’t get to try and die on me, okay? I’ll keep you safe.”


End file.
